What separates the people we are from the people we wish we were? Is it courage? Money? Charisma? Imagination? The Secret Life of Walter Mitty poses that eternal question, and then glosses over it entirely so it can go live out its wildest fantasies.

[Ed: Of course, not everyone feels that way — Peter’s very different response can be found in spoiler-free video form at the end of this post.]

The premise should resonate with anyone who’s ever experienced that heartbreaking disconnect between fantasy and reality. Walter Mitty (played by Ben Stiller, who also directed) is a timid Life Magazine photo editor who escapes his humdrum life through elaborate flights of fancy. In his fantasies, he’s a brave hero who saves his office crush Cheryl (Kristen Wiig) from a burning building, but in real life, he can barely muster up the courage to “wink” at her on eHarmony.

Walter’s journey from the man he is to the man he wants to be makes up the meat of the story, but Stiller’s conflict-free approach turns it into more of a thin gruel than a hearty meal. His Walter transitions seamlessly into a bold adventurer, jetting off to Greenland, Iceland, and Afghanistan at a moment’s notice. Perhaps it’s so easy for Walter because his “reality” in this movie is already pretty damn fantastical. In the film’s world, eHarmony customer service is a man’s best friend, and glowering warlords can be pacified by a piece of cake.

What sets off Walter’s transition is trouble at work. Life Magazine, where he works as a photo editor, is in decline, and layoffs loom as the publication transitions from print to digital. (Yes, in keeping with the dreamy feel, in this universe Life has survived until 2013.) For the very last issue, Walter’s bosses want to use a certain shot by famed photographer Sean O’Connell (Sean Penn). Unfortunately, Walter can’t find it, and he’ll lose his job unless he does.

This gives Walter an excuse to strike up an easy friendship with Cheryl, who obviously likes him from the start. It then takes very little convincing on her part to get Walter on a plane to Greenland, where Sean was last seen, and from there it’s a short leap to diving into shark-infested waters, running into a volcanic eruption, and scaling the Himalayas. As one does.

Despite the movie’s odd lack of tension, it’s tough not to root for Walter and Cheryl, because Stiller and Wiig didn’t get where they are in showbiz without charisma. And Adam Scott helpfully gives us someone to root against as Ted, the douchey, improbably-bearded executive in charge of Life Magazine‘s transition. Kathryn Hahn, Shirley MacLaine, Patton Oswalt, and Adrian Martinez each play small but memorable parts.

Stiller also deserves credit for his ambition. The Secret Life of Walter Mitty tries to blend fantasy, comedy, and drama into a moving package that has something to say about life. Occasionally, it even works. Walter’s fantasies are bizarre but funny; a weird Benjamin Button gag is a comedic high point. When he transitions from dreaming of adventure to experiencing it for real, his travels allow for many breathtaking shots of desolate mountaintops courtesy of cinematographer Stuart Dryburgh.

Even more effective is the movie’s use of music. The Secret Life of Walter Mitty wears its heart on its sleeve, and the soundtrack is appropriately earnest and uplifting. An epic montage of Stiller racing to catch his Greenland flight works because Arcade Fire‘s “Wake Up” is absolutely the perfect song to set it to, and David Bowie‘s “Space Oddity ” is the source of the most two sweetest moments in the film. But when the tunes fade, so do the magical feeling they provided.

Changing one’s life is never as easy as it looks in the movies, but Walter’s 180-degree turn is so sudden and effortless that I wondered what was stopping him from carpe diem-ing in the first place. There’s some halfhearted story about Walter’s dad’s death, but by the time we’ve started to figure out why Walter is the way he is, he’s already become someone else entirely. It’s one thing for daydreams to lack real stakes or conflict, but traditional narrative arcs don’t work unless there’s something for the protagonist to overcome. For all the drastic shifts in Walter’s life, his story feels curiously inert.